1. Field of the Invention
The present invention relates to a motor stator device, and more particularly to a motor stator device with simple coil-winding structure capable of decreasing the cogging torque to improve the noise and energy waste, and capable of improving the convenience and efficiency of the winding operation and thus promoting economic performance and market competitiveness.
2. Related Art
Conventionally, a motor has a stator and a rotor, wherein the stator includes an outer ring portion, a connection portion and an inner ring portion. The outer ring portion is a closed circular body. The inner ring portion has openings that are disposed at intervals. The connection portion is connected between the outer ring portion and the inner ring portion. The inner ring portion is used for receiving the rotor. The connection portion is wound with a metal coil in a lengthwise direction. When current is conducted to the metal coil, the stator forms an electromagnet to drive the rotation of the rotor. Because the outer ring portion is a closed body, the coil-winding machine winds the metal coil in an inner winding manner at both sides of the connection portion from the openings of the inner ring portion. However, this inner winding manner can only be adapted for large-scale inner winding motors. For small-scale inner winding motors, the inner winding manner is usually carried out by hand, especially for the small-scale inner winding motors with high rotation speed. For the small-scale inner winding motors with high rotation speed, the diameter of the metal coil is large and the winding circle number is less. It is quite impossible to perform the inner winding manner for the small-scale inner winding motor by the coil-winding machine. Yet, it seems time-consuming when performing it by hand, thus resulting in low productivity.
Furthermore, there are often problems with unsmooth rotation of rotor resulted from the effect of cogging torque during operations. The cogging torque arises from the magnetic lines of force formed between the stator and the rotor, leading to the variation of torques and the jerky run of the rotor in particular at low speed, therefore causing noise and energy waste.
Moreover, the conventional stator is shaped by stacking a plurality of silicon steel sheets with same structure. Each of the silicon steel sheets has a convex ridge thereon by which the silicon steel sheets are combined as a whole in injection molding. However, the convex ridge is usually designed as circular shape, which brings in instability in combination of the silicon steel sheets, and leads to structural weakness of the stator.